Building a tilt rotor UAV

We see a lot of quadcopters, and even the occasional octocopter around here. But this build does it with just two propellers. It’s a tiltrotor build which allows the two upward-pointing propellers to tilt forward and backward. The real world equivalent of this UAV design that pops to mind is the V-22 Osprey.

The motors are mounted on a beam running perpendicular to the direction of travel. Each of them is mounted on a bearing which can be rotated by a servo motor. They rotate independently of each other, which allows for yaw. Of course roll is controlled by driving the propellers at different speeds and pitch is adjusted by tilting both mounts at the same time.

[Stephen] mentions that the tiltrotor design has several advantages over its relatives that use more than two props. This design costs less to build, uses less electricity, and makes for an easier autopilot implementation. If you want to see it in the air, don’t miss the clip after the break.

Yup, counter-rotating props. The motors are actually inset into foam wings taken from a Radian glider, with custom aluminium bracketing. The wings are connected to a single servo that can tilt them forwards by 90 degrees for forward flight, while pitch stabilisation is done using the flaps whose servos are embedded inside the wings.

I don’t think the Osprey works quite the same way as this. While it may work similarly in hover mode, what differentiates the Osprey is that it has wings that allow it to cruise like a normal airplane. This vastly improves it’s fuel efficiency and, thus, range when compared to helicopters.

Haha, no. I just wanted a different platform to develop my autopilot on. Plus, eventually I want to build one with the capability to completely convert to forward flight. This chassis wouldn’t get me there, so I scrapped it.